back to home page

Notes 2.2


focus - the point where rocks under pressure breaks, making an earthquake
epicenter - the place right above the focus
seismic waves - vibration that travel through the Earth, with energy that is directly above the focus
primary waves - earthquake waves that expand and close together like a spring toy
secondary waves - earthquake waves that goes up and down
surface waves - surface travels more slowly, but the damage is greater
seismograph - records how hard the earthquake shakes
magnitude - a measurement for earthquakes
Mercalli scale - a device to measure earthquake with it's intention
Richter scale - a measurement of size seismic waves
Moment Magnitude scale - used to measure earthquakes no matter how hard it is

Outline


Seismic Waves

  • moves like ripples in a pond
  • travels out in all direction
    • travels from the focus
  • S waves
    • more severe
  • P waves
    • vibrates back and forth
  • Surface waves
    • move more slowly than P waves or S waves

Detecting Seismic Waves

  • seismograph
  • Seismic waves

Measuring Earthquakes

  • Mercalli Scale
  • Rithcher Scale
  • Moment Magnitude Scale

Locating The Epicenter

  • Arrival times af Pwaves and S waves
  • P waves arrive before S waves

ripstick-2.jpg
diagram